Method of and apparatus for blending pulp



Dec. 12, 193-3. R. v. BINGHAM METHOD OF AND APPARATUS FOR BLENDING PULP Filed Sept. 30, 1931 3 Sheets-Sheet 1 //\/Z/E 777R RV. BINGHAM I CK /W Dec. 12, 1933. R. v. BINGHAM METHOD OF AND APPARATUS FOR BLENDING PULP Filed Sept. 30, 1931 3 Sheets-Sheet 2 Dec. 12, 1933. R. v. BINGHAM METHOD OF AND APPARATUS FOR BLENDING PULP Filed Sept. 30, 1931 3 Sheets-Sheet 3 //\/4/ 710 R.V. BINGHAM 6 7- TURNE Patented Dec. 12, 1933.

PATENT OFFICE METHOD OF AND APPARATUS FOR BLENDING PULP Randolph V. Bingham, Portland, Oreg.

Application September 30,1931, Serial No. 566,043

7 Claims. (CI. 92-20) This invention relates generally to paper making, and particul'arly to a method of and apparatus for blending pulp.

The main object of this invention-is the provision of 'a method'of and apparatus for blending pulp so as to provide complete uniformity throughout the contents of a pulp tank with regard to consistency, color and other physical and chemical properties which become factors in the process of making paper from the pulp in question.

This result is attained in the manner set forth in the specification following as illustrated in the accompanying drawings, in which:

Fig. 1 is a somewhat diagrammatic vertical section through the preferred form of pulp blender. V

Fig. 2 is a transverse vertical section along the line -2-2 in Fig. 1. a a

Fig. 3 is a horizontal section along the line 3--3 in Fig. 1.

Fig. 4 is a plan of a modified form of tank.

Fig. 5 is a vertical section taken along the line5-5inFig.4.

Fig. 6 is a section through a modified form of the device. 1

Fig. 7 is a section taken along the line 7-'7 in Fig. 6. I V

Fig. 8 is a diagrammatic view showing a still further modification in which the pump inlet is branched.

Similar numbers of reference refer to similar parts throughout the several views. f

Before entering into a detailed description of this invention it willbe understood that stock mixers and blenders of variou'stypes have been constructed inthe past in which varying degrees of efliciency have been attained. 'The common faults residing insuch devices consist in the 'fact that they merely circulated in a continuous stream, thereby preventing a complete blending of the pulp in the various cooks which may occupy the mixing tank. Various means have been employed to accomplish this blending or mixing operation, and these means have been eitherqineflicient to secure the uniformity referred to, or were of a nature sufiiciently violent to reduce the fiber length and thereby detract from the ultimate strength of the paper made from the stock. 7

Where the agitator lacked the force to break down the fibers it required an undesirable amount of time and power for the blending action. My aim, therefore, has been to attain a complete uniformity in all of the pulp in the tankin the Was shown in Fig. 3).

shortest possible time without detracting from the quality of the pulp itself, or using an unnecessary amount of power.

Referring in detail to Figs. 1 to 3 of the drawings, there is shown a horizontal cylindrical tank 10 supported in a saddle 11. Across the uprights 12 are mounted the horizontal supporting beams 13 on which are mounted the motors 14, 15, 16, 17 and 18 of'pumps l4-A, l5-A, 16A, l'l- A, and 18A whose inlets are near the bottom 29. The pump I l-A is nearest the inlet end 19, which is preferably provided with a rounded lower portion 20, as indicated. The inlet pipe 21, through which the stock enters the tank 10, is shown close to the end 19. The pump 18A is nearest the end 22, near the bottom of which-is an outlet 23. The pumps 14- A to 18A are each provided with an upwardly extending discharge pipe 24 to-28 respectively. The'capacity of the various pumps is preferably equal, although not necessarily so.

The pump 14- -A has a discharge pipe 30 which discharges toward the end 19. The pump 15-A has a discharge pipe 31 which discharges toward the end 19'. "The pump 16A has a discharge pipe 32 which discharges toward the end 19. The pump 17A has an elongated discharge pipe 33 which also discharges toward the end 19, but quite close thereto, for reasons which will become apparent later. The pump -18-A has a pair of discharge pipes 34 and 35, the former discharging toward the end 19 and the latter toward the end 22. Each of the discharge pipes 30, 31, 32, 34 and 35 is preferably branched Theopera'tion of the device is as follows: As-- suming that one or more cooks of stock are admitted to thetank 10 by way of the inlet pipe 21, preferably bringing the level of the pulp in the neighborhood of the line 36, the pumps 14-A to- 18A are operated, each of which picks up its share of the stock and moves it to a different position along thelength'of the tank 10. In other words, if a series of cooks should be admitted to the tank through the inlet 21 and the agitators are operated as described, and each of these cooks varied in consistency and in other properties from all of the other cooks, it follows that asthe first cook is admitted to the tank a portion thereof will be picked up by eachof the pipes 24 to 28 inclusive, then raised to the upper portion of the tank 10 and discharged laterally to a different portion of the tank from whichit was picked up. 7 Obviously, the number of pumps may be varied at will.

the pumps 14A, 15A and 16-A discharge their pulp forwardly toward the inlet end of the tank at different distances therefrom, that the pump 17A, which is farther from the end 19 than are the pumps 14A, 15-A and 16A, discharges its pulp nearest to the end 19.

The function of the pump 18A is to prevent the formation of a dead spot in the mass of pulp near the end 22 and to insure, with the remaining units, that every portion of the pulp within the tank will have a uniform or average blend after the pumps have been operated a sufficient length of time, which in no case need be until the pulp is injured by the agitating action. In other words, regardless of variations in properties (which variations are bound to occur in succeeding cooks of pulp) there will be such a complete intermingling of the various portions of all of the cooks which compose the tankful of stock that a complete uniformity is obtained thereby..

In the form of the device shown in Figs. 4 and 5 the tank 37 is upright and its bottom 38 is formed of an annular trough 39 whose central portion 40 is depressed forming a well fora pipe 41 at whose lower end is mounted a pump 42A which is driven by the motor'42, which pump discharges pulp from the openings 43 over the apron 44. Above the trough 39 are a number of pipes 45 concentrically disposed around the pipe 41. Each pipe 45 has a pump 46A provided with a motor 46 and the pump discharge passes through a. horizontal pipe 47 and through a downtumed elbow 48 which opens into the tank top 49 and discharges in the general direction of the next adjacent pipe 45, although somewhat inwardly-therefrom.

The intake pipe 50 enters one side of the tank 3'7 near the top thereof, and the discharge pipe In this form of the device thereis a constant transfer of pulp about the tank, not by series circulation as isordinarily the case, but by elevating the pulp at one pointand returning it to the tank at a more or less remote point where it is dividedand again picked up by the central pipe 41 and the next outer pipe 45.

Here again we have a complete intermingling of the various streams set up by thepumps employed therein, and while the outward appearance of the two forms of this device is somewhat different there is a, strong similarity intheir principles of operation.

In the form of the device shown in Figs. 6 and .7 the tank 52 is provided with an upright pipe 53 at the lower end of which is mounted the pump 54. Near the middle of the pipe 53 and well toward the top of the tank is a side outlet-pipe 55 provided with a valve 56. The pump 54 is operated by the motor 57 through the shaft 58. On the shaft 58 is also mounted an impeller 59 which is at the upper end of the pipe 53.

It can be seen that any pulp moved upwardly through the pipe 53 by the pump 54 will normally be distributed over the entire area of the tank by the impeller 59.. Obviously, if the valve 56 is open stock will flow from thepipe 55 under the head formed by. the upper portion of the pipe 53that is, its portion above the pipe 55.

In this form of the device the usual inlet pipe 60 and the outlet pipe 61 are provided. Either of the pipes 55 or 61 may be used to draw stock from thetank 52. A suitable housing 01, cage 62 is provided around the impeller 59.

It will be noted that in addition to the fact that The operation of this form of the device is quite similar to that in the form previously described, except that the column of stock rising throughthe pipe 53 is distributed laterally in the form of a spray, or in a number of small streams, thereby insuring a complete mixing and blending of the stock. I

In theform of the device shown in'Fig. 8 the pump 63 is provided with a plurality of horizontal suction pipes 64 which are close to the bottom 65 of the tank. The purpose of these suction pipes is to draw the stock which enters the pump from separated points of the tank bottom and the collected lines of stock are mingled by thepump action and then distributed by the impeller 59. In other words, with this form of the device the stock is picked up at remote points,

mixed and then distributed to remote points within the tank.

Obviously, any number of upright pipes 53 may be employed with a given tank Without departing from the spirit of this invention.

I claim: 7 1. A pulp. mixer consisting of a tank, a plurality of pumps associated with said tank adapted to draw stock from the lower portion thereof at separate points and to return same to said tank between said separated points, and an additional pump having its'discharge extending beyond the sectionzones of several of the first-mentioned pumps.

2. An elongated tank having a series of vertical shaft pumps disposed along the length thereof adapted to raise stock from the bottom of said tank to the upper portion thereof, said tank having inlet and outlet connections at opposite ends thereof,' the pumps nearest the inlet end discharging in the direction of said inlet end within a restricted distance from the point of elevation, and a pump remote from said inlet end having an elongated discharge extending beyond several of said pumps and discharging nearest to said inlet end. 7

3. An elongated tank having a series of vertical shaft-pumps disposed along the length thereof adapted to raise stock from the bottom of said tank to the upper portion thereof, said tank'having inlet and outlet connections at opposite ends thereof, the pumps nearest the inlet end dis- :charging in the direction of said'inlet end within a restricted distance from the point of elevation, a pump remote from said inlet end having an elongated discharge extending beyond several of said pumps and discharging nearest to said inlet end, anda circulating pump at the discharge end of said tank.

4. A method, of mixing stock consisting of elevating it from a common body at a series of points, returning it to said body at intermediate points, and causing certain portions of said stock to be transferred from one point to another not immediately adjacent thereto.

5: A pulp'mixer'consisting of a tank, in combination with an upright riser mounted in said tank, a pump at the bottom of said riser, a laterally discharging impeller at the upper end of said riser, and means for operatingsaid pump and impeller.

v 6. A pulp mixer consisting of a container having an upright riser therein, means for moving pulp upwardly through said riser and discharging same from the upper end thereof, a laterally discharging impeller at the upper end of said riser, and a pulp take-off pipe connected with said shaft at the discharge end of said riser whereby stock which has been collected from various portions of a tank may be elevated and mixed at the same time and further mixed and distributed over the area of the stock body from which pulp is being drawn by said pump.

RANDOLPH V. BINGHAM. 

